static async Task UpdateAccountImageAsync(TwitterContext twitterCtx)
        {
            byte[] imageBytes = File.ReadAllBytes(@"..\..\Images\200xColor_2.png");

            var user = await twitterCtx.UpdateAccountImageAsync(
                imageBytes, "200xColor_2.png", "png", false);

            if (user != null)
                Console.WriteLine("User Image: " + user.ProfileImageUrl); 
        }